Indian Defense: London System: what should White play?

In the Indian Defense: London System, White often considers prophylactic pawn play, development, or solidifying the center. The engine slightly favors h3 (evaluated at +0.56) to secure a retreat square for the f4 against potential harassment. While e3 is the predominant choice across recorded games, h3 maintains a solid grip and White scores 56.1% from this position.

Prophylaxis with h3 and h4

Although h3 appears in only 6.0% of recorded games (5.0K recorded), it offers a clear strategic benefit by anticipating ideas involving knight jumps toward the h5 square. An illustrative engine continuation demonstrates a typical queenside and central expansion: h3 c5 e3 b6 Na3 a6. A sharper thrust, h4, ranks highest in evaluation at +0.58, continuing along the path h4 c5 e3 b6 Na3 cxd4, though game count data is unavailable for this specific advance.

Classical Development with e3 and Nbd2

The overwhelming practical choice is e3, chosen in 67.8% of recorded games (56K recorded) with an evaluation of +0.41 and a 55.4% score for White. This move supports the d4 pawn directly, as seen in the illustrative line e3 Nh5 Nbd2 Nxf4 exf4 d5, where White accepts doubled pawns to control the center. Alternatively, Nbd2 is selected in 25.7% of games (21K recorded) with an evaluation of +0.41 and a 56.1% score, leading to continuations such as Nbd2 Nh5 Bg3 d5 Qc2 Nd7. A rare fifth option, Qc2, occurs in just 0.5% of games (454 recorded) and yields Qc2 Nh5 Bd2 d5 c4 Nf6 with an evaluation of +0.37 and a 56.6% score.